The carpal tunnel is a small passageway in the wrist under the skin consisting of bones and tendons of the wrist on the palmar side of the wrist. Nine tendons and one nerve pass through the carpal tunnel toward the hand. If the carpal tunnel is narrowed or the internal pressure thereof is increased for some reasons, the median nerve passing through the carpal tunnel would be compressed, resulting in various symptoms in palm and fingers in the distribution of the median nerve, i.e., a common medical condition known as carpal tunnel syndrome.
At the initial stage of the carpal tunnel syndrome, the symptoms can be fixed by injecting steroids into the carpal tunnel. If, however, the disease more develops and cannot be cured by the steroids injection, surgical treatment through should be considered.
Conventionally, it has been attempted to treat the carpal tunnel syndrome through a surgical operation of incising the skin of the wrist so as to expose flexor retinaculum 10 that arches over the carpal tunnel and cutting a part of the flexor retinaculum 10. This surgery, however, has problems in that the incision range of the skin is excessively wide and recovery takes long time.
In this regard, recently, an endoscopic operation of inserting an endoscope to a space below the flexor retinaculum and cutting the flexor retinaculum is attempted. This surgery, however, is also problematic in that the incision site for the insertion of the endoscope is still not small enough, the operation time is long due to many difficulties in cutting the flexor retinaculum, and recovery still takes a quite long time.